1 // SPDX-License-Identifier: GPL-2.0-only
3 * Record and handle CPU attributes.
5 * Copyright (C) 2014 ARM Ltd.
7 #include <asm/arch_timer.h>
10 #include <asm/cputype.h>
11 #include <asm/cpufeature.h>
12 #include <asm/fpsimd.h>
14 #include <linux/bitops.h>
15 #include <linux/bug.h>
16 #include <linux/compat.h>
17 #include <linux/elf.h>
18 #include <linux/init.h>
19 #include <linux/kernel.h>
20 #include <linux/of_platform.h>
21 #include <linux/personality.h>
22 #include <linux/preempt.h>
23 #include <linux/printk.h>
24 #include <linux/seq_file.h>
25 #include <linux/sched.h>
26 #include <linux/smp.h>
27 #include <linux/delay.h>
30 * In case the boot CPU is hotpluggable, we record its initial state and
31 * current state separately. Certain system registers may contain different
32 * values depending on configuration at or after reset.
34 DEFINE_PER_CPU(struct cpuinfo_arm64, cpu_data);
35 static struct cpuinfo_arm64 boot_cpu_data;
37 static const char *icache_policy_str[] = {
38 [ICACHE_POLICY_VPIPT] = "VPIPT",
39 [ICACHE_POLICY_RESERVED] = "RESERVED/UNKNOWN",
40 [ICACHE_POLICY_VIPT] = "VIPT",
41 [ICACHE_POLICY_PIPT] = "PIPT",
44 unsigned long __icache_flags;
46 static const char *const hwcap_str[] = {
47 [KERNEL_HWCAP_FP] = "fp",
48 [KERNEL_HWCAP_ASIMD] = "asimd",
49 [KERNEL_HWCAP_EVTSTRM] = "evtstrm",
50 [KERNEL_HWCAP_AES] = "aes",
51 [KERNEL_HWCAP_PMULL] = "pmull",
52 [KERNEL_HWCAP_SHA1] = "sha1",
53 [KERNEL_HWCAP_SHA2] = "sha2",
54 [KERNEL_HWCAP_CRC32] = "crc32",
55 [KERNEL_HWCAP_ATOMICS] = "atomics",
56 [KERNEL_HWCAP_FPHP] = "fphp",
57 [KERNEL_HWCAP_ASIMDHP] = "asimdhp",
58 [KERNEL_HWCAP_CPUID] = "cpuid",
59 [KERNEL_HWCAP_ASIMDRDM] = "asimdrdm",
60 [KERNEL_HWCAP_JSCVT] = "jscvt",
61 [KERNEL_HWCAP_FCMA] = "fcma",
62 [KERNEL_HWCAP_LRCPC] = "lrcpc",
63 [KERNEL_HWCAP_DCPOP] = "dcpop",
64 [KERNEL_HWCAP_SHA3] = "sha3",
65 [KERNEL_HWCAP_SM3] = "sm3",
66 [KERNEL_HWCAP_SM4] = "sm4",
67 [KERNEL_HWCAP_ASIMDDP] = "asimddp",
68 [KERNEL_HWCAP_SHA512] = "sha512",
69 [KERNEL_HWCAP_SVE] = "sve",
70 [KERNEL_HWCAP_ASIMDFHM] = "asimdfhm",
71 [KERNEL_HWCAP_DIT] = "dit",
72 [KERNEL_HWCAP_USCAT] = "uscat",
73 [KERNEL_HWCAP_ILRCPC] = "ilrcpc",
74 [KERNEL_HWCAP_FLAGM] = "flagm",
75 [KERNEL_HWCAP_SSBS] = "ssbs",
76 [KERNEL_HWCAP_SB] = "sb",
77 [KERNEL_HWCAP_PACA] = "paca",
78 [KERNEL_HWCAP_PACG] = "pacg",
79 [KERNEL_HWCAP_DCPODP] = "dcpodp",
80 [KERNEL_HWCAP_SVE2] = "sve2",
81 [KERNEL_HWCAP_SVEAES] = "sveaes",
82 [KERNEL_HWCAP_SVEPMULL] = "svepmull",
83 [KERNEL_HWCAP_SVEBITPERM] = "svebitperm",
84 [KERNEL_HWCAP_SVESHA3] = "svesha3",
85 [KERNEL_HWCAP_SVESM4] = "svesm4",
86 [KERNEL_HWCAP_FLAGM2] = "flagm2",
87 [KERNEL_HWCAP_FRINT] = "frint",
88 [KERNEL_HWCAP_SVEI8MM] = "svei8mm",
89 [KERNEL_HWCAP_SVEF32MM] = "svef32mm",
90 [KERNEL_HWCAP_SVEF64MM] = "svef64mm",
91 [KERNEL_HWCAP_SVEBF16] = "svebf16",
92 [KERNEL_HWCAP_I8MM] = "i8mm",
93 [KERNEL_HWCAP_BF16] = "bf16",
94 [KERNEL_HWCAP_DGH] = "dgh",
95 [KERNEL_HWCAP_RNG] = "rng",
96 [KERNEL_HWCAP_BTI] = "bti",
97 [KERNEL_HWCAP_MTE] = "mte",
98 [KERNEL_HWCAP_ECV] = "ecv",
99 [KERNEL_HWCAP_AFP] = "afp",
100 [KERNEL_HWCAP_RPRES] = "rpres",
104 #define COMPAT_KERNEL_HWCAP(x) const_ilog2(COMPAT_HWCAP_ ## x)
105 static const char *const compat_hwcap_str[] = {
106 [COMPAT_KERNEL_HWCAP(SWP)] = "swp",
107 [COMPAT_KERNEL_HWCAP(HALF)] = "half",
108 [COMPAT_KERNEL_HWCAP(THUMB)] = "thumb",
109 [COMPAT_KERNEL_HWCAP(26BIT)] = NULL, /* Not possible on arm64 */
110 [COMPAT_KERNEL_HWCAP(FAST_MULT)] = "fastmult",
111 [COMPAT_KERNEL_HWCAP(FPA)] = NULL, /* Not possible on arm64 */
112 [COMPAT_KERNEL_HWCAP(VFP)] = "vfp",
113 [COMPAT_KERNEL_HWCAP(EDSP)] = "edsp",
114 [COMPAT_KERNEL_HWCAP(JAVA)] = NULL, /* Not possible on arm64 */
115 [COMPAT_KERNEL_HWCAP(IWMMXT)] = NULL, /* Not possible on arm64 */
116 [COMPAT_KERNEL_HWCAP(CRUNCH)] = NULL, /* Not possible on arm64 */
117 [COMPAT_KERNEL_HWCAP(THUMBEE)] = NULL, /* Not possible on arm64 */
118 [COMPAT_KERNEL_HWCAP(NEON)] = "neon",
119 [COMPAT_KERNEL_HWCAP(VFPv3)] = "vfpv3",
120 [COMPAT_KERNEL_HWCAP(VFPV3D16)] = NULL, /* Not possible on arm64 */
121 [COMPAT_KERNEL_HWCAP(TLS)] = "tls",
122 [COMPAT_KERNEL_HWCAP(VFPv4)] = "vfpv4",
123 [COMPAT_KERNEL_HWCAP(IDIVA)] = "idiva",
124 [COMPAT_KERNEL_HWCAP(IDIVT)] = "idivt",
125 [COMPAT_KERNEL_HWCAP(VFPD32)] = NULL, /* Not possible on arm64 */
126 [COMPAT_KERNEL_HWCAP(LPAE)] = "lpae",
127 [COMPAT_KERNEL_HWCAP(EVTSTRM)] = "evtstrm",
130 #define COMPAT_KERNEL_HWCAP2(x) const_ilog2(COMPAT_HWCAP2_ ## x)
131 static const char *const compat_hwcap2_str[] = {
132 [COMPAT_KERNEL_HWCAP2(AES)] = "aes",
133 [COMPAT_KERNEL_HWCAP2(PMULL)] = "pmull",
134 [COMPAT_KERNEL_HWCAP2(SHA1)] = "sha1",
135 [COMPAT_KERNEL_HWCAP2(SHA2)] = "sha2",
136 [COMPAT_KERNEL_HWCAP2(CRC32)] = "crc32",
138 #endif /* CONFIG_COMPAT */
140 static int c_show(struct seq_file *m, void *v)
143 bool compat = personality(current->personality) == PER_LINUX32;
144 struct device_node *np;
149 for_each_online_cpu(i) {
150 struct cpuinfo_arm64 *cpuinfo = &per_cpu(cpu_data, i);
151 u32 midr = cpuinfo->reg_midr;
154 * glibc reads /proc/cpuinfo to determine the number of
155 * online processors, looking for lines beginning with
156 * "processor". Give glibc what it expects.
158 seq_printf(m, "processor\t: %d\n", i);
160 seq_printf(m, "model name\t: ARMv8 Processor rev %d (%s)\n",
161 MIDR_REVISION(midr), COMPAT_ELF_PLATFORM);
163 seq_printf(m, "BogoMIPS\t: %lu.%02lu\n",
164 loops_per_jiffy / (500000UL/HZ),
165 loops_per_jiffy / (5000UL/HZ) % 100);
168 * Dump out the common processor features in a single line.
169 * Userspace should read the hwcaps with getauxval(AT_HWCAP)
170 * rather than attempting to parse this, but there's a body of
171 * software which does already (at least for 32-bit).
173 seq_puts(m, "Features\t:");
176 for (j = 0; j < ARRAY_SIZE(compat_hwcap_str); j++) {
177 if (compat_elf_hwcap & (1 << j)) {
179 * Warn once if any feature should not
180 * have been present on arm64 platform.
182 if (WARN_ON_ONCE(!compat_hwcap_str[j]))
185 seq_printf(m, " %s", compat_hwcap_str[j]);
189 for (j = 0; j < ARRAY_SIZE(compat_hwcap2_str); j++)
190 if (compat_elf_hwcap2 & (1 << j))
191 seq_printf(m, " %s", compat_hwcap2_str[j]);
192 #endif /* CONFIG_COMPAT */
194 for (j = 0; j < ARRAY_SIZE(hwcap_str); j++)
195 if (cpu_have_feature(j))
196 seq_printf(m, " %s", hwcap_str[j]);
200 seq_printf(m, "CPU implementer\t: 0x%02x\n",
201 MIDR_IMPLEMENTOR(midr));
202 seq_printf(m, "CPU architecture: 8\n");
203 seq_printf(m, "CPU variant\t: 0x%x\n", MIDR_VARIANT(midr));
204 seq_printf(m, "CPU part\t: 0x%03x\n", MIDR_PARTNUM(midr));
205 seq_printf(m, "CPU revision\t: %d\n\n", MIDR_REVISION(midr));
208 seq_printf(m, "Hardware\t: BCM2835\n");
210 np = of_find_node_by_path("/system");
212 if (!of_property_read_u32(np, "linux,revision", &revision))
213 seq_printf(m, "Revision\t: %04x\n", revision);
217 np = of_find_node_by_path("/");
219 if (!of_property_read_string(np, "serial-number",
221 seq_printf(m, "Serial\t\t: %s\n", serial);
222 if (!of_property_read_string(np, "model",
224 seq_printf(m, "Model\t\t: %s\n", model);
231 static void *c_start(struct seq_file *m, loff_t *pos)
233 return *pos < 1 ? (void *)1 : NULL;
236 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
242 static void c_stop(struct seq_file *m, void *v)
246 const struct seq_operations cpuinfo_op = {
254 static struct kobj_type cpuregs_kobj_type = {
255 .sysfs_ops = &kobj_sysfs_ops,
259 * The ARM ARM uses the phrase "32-bit register" to describe a register
260 * whose upper 32 bits are RES0 (per C5.1.1, ARM DDI 0487A.i), however
261 * no statement is made as to whether the upper 32 bits will or will not
262 * be made use of in future, and between ARM DDI 0487A.c and ARM DDI
263 * 0487A.d CLIDR_EL1 was expanded from 32-bit to 64-bit.
265 * Thus, while both MIDR_EL1 and REVIDR_EL1 are described as 32-bit
266 * registers, we expose them both as 64 bit values to cater for possible
267 * future expansion without an ABI break.
269 #define kobj_to_cpuinfo(kobj) container_of(kobj, struct cpuinfo_arm64, kobj)
270 #define CPUREGS_ATTR_RO(_name, _field) \
271 static ssize_t _name##_show(struct kobject *kobj, \
272 struct kobj_attribute *attr, char *buf) \
274 struct cpuinfo_arm64 *info = kobj_to_cpuinfo(kobj); \
276 if (info->reg_midr) \
277 return sprintf(buf, "0x%016llx\n", info->reg_##_field); \
281 static struct kobj_attribute cpuregs_attr_##_name = __ATTR_RO(_name)
283 CPUREGS_ATTR_RO(midr_el1, midr);
284 CPUREGS_ATTR_RO(revidr_el1, revidr);
286 static struct attribute *cpuregs_id_attrs[] = {
287 &cpuregs_attr_midr_el1.attr,
288 &cpuregs_attr_revidr_el1.attr,
292 static const struct attribute_group cpuregs_attr_group = {
293 .attrs = cpuregs_id_attrs,
294 .name = "identification"
297 static int cpuid_cpu_online(unsigned int cpu)
301 struct cpuinfo_arm64 *info = &per_cpu(cpu_data, cpu);
303 dev = get_cpu_device(cpu);
308 rc = kobject_add(&info->kobj, &dev->kobj, "regs");
311 rc = sysfs_create_group(&info->kobj, &cpuregs_attr_group);
313 kobject_del(&info->kobj);
318 static int cpuid_cpu_offline(unsigned int cpu)
321 struct cpuinfo_arm64 *info = &per_cpu(cpu_data, cpu);
323 dev = get_cpu_device(cpu);
326 if (info->kobj.parent) {
327 sysfs_remove_group(&info->kobj, &cpuregs_attr_group);
328 kobject_del(&info->kobj);
334 static int __init cpuinfo_regs_init(void)
338 for_each_possible_cpu(cpu) {
339 struct cpuinfo_arm64 *info = &per_cpu(cpu_data, cpu);
341 kobject_init(&info->kobj, &cpuregs_kobj_type);
344 ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "arm64/cpuinfo:online",
345 cpuid_cpu_online, cpuid_cpu_offline);
347 pr_err("cpuinfo: failed to register hotplug callbacks.\n");
352 device_initcall(cpuinfo_regs_init);
354 static void cpuinfo_detect_icache_policy(struct cpuinfo_arm64 *info)
356 unsigned int cpu = smp_processor_id();
357 u32 l1ip = CTR_L1IP(info->reg_ctr);
360 case ICACHE_POLICY_PIPT:
362 case ICACHE_POLICY_VPIPT:
363 set_bit(ICACHEF_VPIPT, &__icache_flags);
365 case ICACHE_POLICY_RESERVED:
366 case ICACHE_POLICY_VIPT:
367 /* Assume aliasing */
368 set_bit(ICACHEF_ALIASING, &__icache_flags);
372 pr_info("Detected %s I-cache on CPU%d\n", icache_policy_str[l1ip], cpu);
375 static void __cpuinfo_store_cpu_32bit(struct cpuinfo_32bit *info)
377 info->reg_id_dfr0 = read_cpuid(ID_DFR0_EL1);
378 info->reg_id_dfr1 = read_cpuid(ID_DFR1_EL1);
379 info->reg_id_isar0 = read_cpuid(ID_ISAR0_EL1);
380 info->reg_id_isar1 = read_cpuid(ID_ISAR1_EL1);
381 info->reg_id_isar2 = read_cpuid(ID_ISAR2_EL1);
382 info->reg_id_isar3 = read_cpuid(ID_ISAR3_EL1);
383 info->reg_id_isar4 = read_cpuid(ID_ISAR4_EL1);
384 info->reg_id_isar5 = read_cpuid(ID_ISAR5_EL1);
385 info->reg_id_isar6 = read_cpuid(ID_ISAR6_EL1);
386 info->reg_id_mmfr0 = read_cpuid(ID_MMFR0_EL1);
387 info->reg_id_mmfr1 = read_cpuid(ID_MMFR1_EL1);
388 info->reg_id_mmfr2 = read_cpuid(ID_MMFR2_EL1);
389 info->reg_id_mmfr3 = read_cpuid(ID_MMFR3_EL1);
390 info->reg_id_mmfr4 = read_cpuid(ID_MMFR4_EL1);
391 info->reg_id_mmfr5 = read_cpuid(ID_MMFR5_EL1);
392 info->reg_id_pfr0 = read_cpuid(ID_PFR0_EL1);
393 info->reg_id_pfr1 = read_cpuid(ID_PFR1_EL1);
394 info->reg_id_pfr2 = read_cpuid(ID_PFR2_EL1);
396 info->reg_mvfr0 = read_cpuid(MVFR0_EL1);
397 info->reg_mvfr1 = read_cpuid(MVFR1_EL1);
398 info->reg_mvfr2 = read_cpuid(MVFR2_EL1);
401 static void __cpuinfo_store_cpu(struct cpuinfo_arm64 *info)
403 info->reg_cntfrq = arch_timer_get_cntfrq();
405 * Use the effective value of the CTR_EL0 than the raw value
406 * exposed by the CPU. CTR_EL0.IDC field value must be interpreted
407 * with the CLIDR_EL1 fields to avoid triggering false warnings
408 * when there is a mismatch across the CPUs. Keep track of the
409 * effective value of the CTR_EL0 in our internal records for
410 * accurate sanity check and feature enablement.
412 info->reg_ctr = read_cpuid_effective_cachetype();
413 info->reg_dczid = read_cpuid(DCZID_EL0);
414 info->reg_midr = read_cpuid_id();
415 info->reg_revidr = read_cpuid(REVIDR_EL1);
417 info->reg_id_aa64dfr0 = read_cpuid(ID_AA64DFR0_EL1);
418 info->reg_id_aa64dfr1 = read_cpuid(ID_AA64DFR1_EL1);
419 info->reg_id_aa64isar0 = read_cpuid(ID_AA64ISAR0_EL1);
420 info->reg_id_aa64isar1 = read_cpuid(ID_AA64ISAR1_EL1);
421 info->reg_id_aa64isar2 = read_cpuid(ID_AA64ISAR2_EL1);
422 info->reg_id_aa64mmfr0 = read_cpuid(ID_AA64MMFR0_EL1);
423 info->reg_id_aa64mmfr1 = read_cpuid(ID_AA64MMFR1_EL1);
424 info->reg_id_aa64mmfr2 = read_cpuid(ID_AA64MMFR2_EL1);
425 info->reg_id_aa64pfr0 = read_cpuid(ID_AA64PFR0_EL1);
426 info->reg_id_aa64pfr1 = read_cpuid(ID_AA64PFR1_EL1);
427 info->reg_id_aa64zfr0 = read_cpuid(ID_AA64ZFR0_EL1);
429 if (id_aa64pfr1_mte(info->reg_id_aa64pfr1))
430 info->reg_gmid = read_cpuid(GMID_EL1);
432 if (id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0))
433 __cpuinfo_store_cpu_32bit(&info->aarch32);
435 if (IS_ENABLED(CONFIG_ARM64_SVE) &&
436 id_aa64pfr0_sve(info->reg_id_aa64pfr0))
437 info->reg_zcr = read_zcr_features();
439 cpuinfo_detect_icache_policy(info);
442 void cpuinfo_store_cpu(void)
444 struct cpuinfo_arm64 *info = this_cpu_ptr(&cpu_data);
445 __cpuinfo_store_cpu(info);
446 update_cpu_features(smp_processor_id(), info, &boot_cpu_data);
449 void __init cpuinfo_store_boot_cpu(void)
451 struct cpuinfo_arm64 *info = &per_cpu(cpu_data, 0);
452 __cpuinfo_store_cpu(info);
454 boot_cpu_data = *info;
455 init_cpu_features(&boot_cpu_data);